1. Field of the Invention
This invention relates to decorative bodies having generally spherical shapes defined by arcuately spaced ribs made of moldable thermoplastic resins. More particularly, the invention relates to an expandable structure that can be packaged and shipped in a substantially flat orientation, and then quickly and conveniently expanded by the user to produce a spherically shaped body.
2. Description of Related Art
Decorative spheres having a plurality of circumferentially spaced arcuate ribs are well known, having been disclosed, for example, in U.S. Pat. No. 5,645,343. Such spheres can be used as a support structure for the display of decorative lights linked together in light strings that are also well known in the art. A disadvantage of the spheres disclosed in U.S. Pat. No. 5,645,343 is that they comprise many different parts that must be assembled by the user because of the economic disadvantages associated with shipping the relatively voluminous assembled spheres. The structures disclosed in U.S. Pat. No. 5,645,343 also have the disadvantage of unattractive, vertically disposed ribs inside the sphere that contribute to the material cost and weight of the finished product.
Other decorative structures useful for displaying lights in a spherical array are disclosed, for example, in U.S. Pat. Nos. 5,629,057; 6,70,991 and 6,135,617.
The invention disclosed herein is a spherically shaped structure preferably comprising a plurality of substantially identical, pivotably interconnected, elongate ribs that lie in substantially coplanar, contiguous relation to each other when folded, but are readily expandable to form a discontinuous, substantially spherical body having a plurality of circumferentially spaced ribs and top and bottom hub sections formed by end panels unitarily molded onto the ends of each rib. Each sphere will desirably comprise at least four, and preferably at least six or eight, ribs. Generally speaking, larger diameter spheres will preferably comprise a greater number of ribs than smaller diameter spheres. The pivotable interconnection between adjacent ribs is preferably achieved by providing tabs on the end panels, the tabs being cooperatively alignable with mating tabs of adjacent ribs, permitting such cooperatively aligned tabs to be pivotably connected to form an integral structure. The end panels of each molded rib preferably further comprise cooperatively engageable first and second edges having stepped cross-sections that, when engaged, form substantially continuous upper and lower hub surfaces providing strength and rigidity to the expanded sphere. Once the sphere is expanded, a pin or other similarly effective, releasable locking element is desirably used to interconnect the last two cooperatively aligned tabs of each of the top and bottom hub surfaces.